P0296 Code: Cylinder 12 Fuel Injector Contribution/Balance
🟠 Moderate severity · drivable
Drivable, but the engine may run rough or shake at idle. Fix it soon to protect the catalytic converter.
What P0296 means
The computer compares how much power each cylinder makes at idle. Cylinder 12 is contributing too little or too much, which usually points to a fuel injector on that cylinder that is clogged, worn, or leaking.
Symptoms
- Check engine light on
- Rough idle or shaking
- Loss of power
- Poor fuel economy
Common causes
- most common: Clogged or faulty fuel injector on cylinder 12
- common: Injector wiring or connector problem on cylinder 12
- less common: Vacuum leak or air intake issue on that cylinder
- less common: Low compression in cylinder 12
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Run an injector balance test to confirm the problem | Mechanic | $50–150 |
| Clean or replace the cylinder 12 fuel injector | Mechanic | $100–300 |
| Check and repair injector wiring or connectors | Mechanic | $50–200 |
| Run a compression test on cylinder 12 | Mechanic | $100–200 |
Frequently asked questions
Can I drive with P0296?
Yes, but the engine may idle rough or shake. Fix it soon so the extra fuel doesn't damage the catalytic converter.
What does a contribution/balance code mean?
The computer found that cylinder 12 isn't adding the same amount of power as the other cylinders, usually because of a fuel injector problem.
What usually fixes P0296?
Replacing or cleaning the cylinder 12 fuel injector fixes most cases.
Related codes
P0294
P0294 Code: Cylinder 12 Fuel Injector Circuit Low
P0295P0295 Code: Cylinder 12 Fuel Injector Circuit High
P0312P0312 Code: Cylinder 12 Misfire Detected
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.